The number of people getting diseases from ticks and mosquitoes in the United States has more than tripled from 2004 to 2016 according to the latest report from The Centers for Disease Control.The CDC report is the first comprehensive look at all of the diseases that are carried by mosquitoes, ticks and fleas, and which are showing up increasingly across the U.S.
Diseases such as Lyme, West Nile, Zika and dengue are on the rise and the U.S. is not fully prepared to control the spread, the report finds.
Mosquitoes and ticks are increasing and moving into new areas the authors say, but the federal agency doesn’t mention climate change as a reason for the spread.
But Dartmouth College biology professor Matt Ayers says as the climate warms, and our winters become less severe, we should expect to see more ticks in northern New England.
“Climate change certainly has to be treated as a realistic possibility,” he says. “It’s one of a couple of possibilities.”
"We've seen an increase here in Vermont over the last couple of years in tick-borne diseases in particular." — Bradely Tompkins, Vermont Department of Health
Ticks mainly feed on the blood of deer and rodents, and Ayres says other human impacts on the environment are changing the living and roaming patterns of deer and mice.
The report also points to more overseas travel as a reason why some diseases are spreading across the U.S.
But the bottom line is that scientists don’t completely understand why there are more ticks or why more ticks are carrying diseases.
“To my knowledge it has not been specifically addressed with research,” says Ayers. “It’s actually amazing how little we know about the ecology of these animals that are so important to people.”
Lyme
The CDC says Lyme disease is one of the most common tick-borne diseases and in 2016, Vermont had the second highest rate of reported Lyme disease cases in the U.S.
And the number of reported cases in Vermont has increased dramatically over the past 10 years. There were about 100 cases across the state in 2006.
Ten years later, there were more than 500.
Vermont Department of Health Infectious Disease Epidemiologist and Program Chief Bradley Tompkins says the national numbers in the CDC report reflect what he’s seeing across this state.
“We’ve seen an increase here in Vermont over the last couple of years in tick-borne diseases in particular,” he said. “So it’s not the sort of trend we want to see, but it didn’t come as a big surprise.”
The health department says there are five species ticks that bite humans and four of those carry disease.
The health department says the best way to avoid tick bites is by using an insect repellent, checking the body daily for ticks, and limiting exposure to tick habitat.
But the department says 99 percent of all tick-borne diseases reported in Vermont are caused by the black-legged tick.
In recent studies, over half of the black-legged ticks collected in Vermont, tested positive for the bacterium that causes Lyme disease.
Southern Vermont has had more confirmed Lyme disease cases since 2015 than any other region of the state.
The health department says the best way to avoid tick bites is by using an insect repellent, checking the body daily for ticks, and limiting exposure to tick habitat.
